Presence of active hepatitis associated with liver cirrhosis is a risk factor for mortality caused by posthepatectomy liver failure

The histologic activity of associated hepatitis was examined in 285 patients who underwent hepatectomy for hepatocellular carcinoma (HCC), to determine if the histologic activity is an independent risk factor for postoperative mortality due to liver failure. The proportion of patients with liver cirrhosis who died due to liver failure (6/180, 3.3%) was not different from that of patients with chronic hepatitis (2/68, 2.9%). However, mortality was higher in patients with liver cirrhosis and active hepatitis (4/46, 8.7%) than in those with cirrhosis and inactive hepatitis (2/134, 1.5%, P < 0.05). Such difference was not observed in the chronic hepatitis group. Multivariate analysis showed that clearance of indocyanine green at 15 min (ICGR15) and activity of hepatitis were two independent risk factors for postoperative mortality due to liver failure. In conclusion, histologic activity of associated hepatitis should be taken into account in hepatic resection of HCC in cirrhotic liver, in addition to the functional reserve of the liver.

The inhibitory effect of prostaglandin E1 on oxidative stress-induced hepatocyte injury evaluated by calpain-mu activation

BACKGROUND

Prostaglandin E1 (PGE1) is known to inhibit ischemia-reperfusion injury of the liver. The calcium-dependent neutral proteinase, calpain-mu, is involved in oxidative stress-induced hepatocyte injury. We investigated the mechanisms of cytoprotection by PGE1, focusing on the elevation of intracellular calcium ([Ca2+]i), activation of calpain-mu, and calpain-mu-mediated activation of protein kinase C-alpha (PKC-alpha).

METHODS

Cultured hepatocytes were treated with various amounts of PGE1 (0, 0.1, 1.0, 10, and 100 ng/ml) for 30 min and subsequently with 0.5 mM tert-butyl hydroperoxide (TBHP). Cell injury was evaluated by the release of lactate dehydrogenase. Plasma membrane bleb formation was examined by phase contrast microscopy. Activation of calpain-mu and limited degradation of PKC-alpha was evaluated by Western blotting using antibodies that specifically recognize the amino-terminal regions of calpain-mu and PKC-alpha. [Ca2+]i was measured by confocal microscopy using Fluo-3AM.

RESULTS

LDH release from cells treated with 10 ng/ml PGE1 was significantly lower than from untreated cells (135 +/- 12 vs. 258 +/- 18 IU/L, respectively; P < 0.05). Morphologically, many blebs were observed in untreated cells, but very few were seen in those treated with 10 ng/ml PGE1. Western blotting revealed that the amount of activated calpain-mu and [Ca2+]i increased up to 1,300 nM at 35 min after the addition of TBHP (0.5 mmol/L) in control experiments (without PGE1). PGE1 (10 ng/ml) delayed the rise in [Ca2+]i for about 30 min, but did not suppress it completely. PKC-alpha decreased in experiments using PGE1 (10 ng/ml).

CONCLUSION

PGE1 exerts its cytoprotective effect in TBHP-induced hepatocyte injury partly by inhibiting Ca2+-calpain-mu-mediated mechanisms.

A new class of neurotoxin from wasp venom slows inactivation of sodium current

The effects of alpha-pompilidotoxin (alpha-PMTX), a new neurotoxin isolated from the venom of a solitary wasp, were studied on the neuromuscular synapses in lobster walking leg and the rat trigeminal ganglion (TG) neurons. Paired intracellular recordings from the presynaptic axon terminals and the innervating lobster leg muscles revealed that alpha-PMTX induced long bursts of action potentials in the presynaptic axon, which resulted in facilitated excitatory and inhibitory synaptic transmission. The action of alpha-PMTX was distinct from that of other known facilitatory presynaptic toxins, including sea anemone toxins and alpha-scorpion toxins, which modify the fast inactivation of Na+ current. We further characterized the action of alpha-PMTX on Na+ channels by whole-cell recordings from rat trigeminal neurons. We found that alpha-PMTX slowed the Na+ channels inactivation process without changing the peak current-voltage relationship or the activation time course of tetrodotoxin (TTX)-sensitive Na+ currents, and that alpha-PMTX had voltage-dependent effects on the rate of recovery from Na+ current inactivation and deactivating tail currents. The results suggest that alpha-PMTX slows or blocks conformational changes required for fast inactivation of the Na+ channels on the extracellular surface. The simple structure of alpha-PMTX, consisting of 13 amino acids, would be advantageous for understanding the functional architecture of Na+ channel protein.

Anergic T cells generated in vitro suppress rejection response to islet allografts

BACKGROUND

Induction of antigen-specific unresponsiveness to grafts is the ultimate goal for organ transplantation. It has been shown that anergic T cells generated in vivo can be transferred as suppressor cells. Anergic cells generated in vitro have never been successfully used to prevent allograft rejection in vivo. We examined whether anergic cells generated in vitro by blocking CD28/B7 costimulatory pathway can suppress allograft rejection in vivo.

METHODS

Anergic T cells were generated in vitro by the addition of anti-B7-1 and anti-B7-2 monoclonal antibodies (mAbs) to primary mixed lymphocyte reaction (MLR) consisting of C57BL/6 (B6) splenocytes as responder and irradiated BALB/c splenocytes as stimulator. We tested the ability of these cells to respond to various stimuli and to suppress alloreactive T-cell responses in vitro. For in vivo studies, 4x10(7) anergic cells were injected intravenously immediately after transplantation of BALB/c islets under the renal subcapsular space of streptozotocin-induced diabetic and 2.5-Gy X-irradiated B6 mice.

RESULTS

Anergic cells treated with both mAbs in the primary MLR did not proliferate in secondary MLR against BALB/c and third-party C3H/He stimulators. The cells also failed to respond to immobilized anti-CD3 mAb, although they proliferated in response to concanavalin A or phorbol myristate acetate + ionomycin. The anergic state was reversed by the addition of exogenous IL-2. Furthermore, these cells suppressed the proliferation of naive B6 T cells against either the same (BALB/c) or third-party (C3H/He) stimulator cells. In in vivo studies, irradiated B6 mice rejected BALB/c islet allografts acutely with a mean survival time of 27.0+/-8.3 days, whereas two of six animals injected with the anergic cells accepted the allografts indefinitely (>100 days) with a mean survival time of 52.0+/-38.2 days.

CONCLUSIONS

Anergic cells generated in vitro by blocking CD28/B7 costimulatory pathway suppress islet allograft rejection after adoptive transfer. This procedure might be clinically useful for promoting allograft survival.

Detection and mapping of mismatched base pairs in DNA molecules by atomic force microscopy

Attempts were made to apply atomic force microscopy (AFM) imaging to the detection and mapping of the sites of base substitutions in DNA molecules. In essence, DNA fragments to be examined for possible base substitutions were mixed with an equal amount of a corresponding DNA standard and subjected to heat denaturation and subsequent annealing. The reassociated DNA was incubated with MutS protein, a protein that recognizes and binds to mismatched base pairs in duplex DNA. Bound MutS protein molecules were then detected by AFM and their positions along the DNA molecules were determined by calculating the distance from one of the DNA termini, which had been tagged with a biotin-avidin complex. Base substitutions present in DNA molecules >1 kb were effectively detected by this procedure, and the positions determined were in good agreement with the actual mutation sites. This method is quite simple, has virtually no limitations on the size of DNA fragments to be examined and requires only a very small amount of DNA sample.

Induction of unresponsiveness to islet xenograft by MMC treatment of graft and blockage of LFA-1/ICAM-1 pathway

BACKGROUND

Induction of unresponsiveness to graft is one of major interest in xenotransplantation. Two different modalities [direct graft treatment by mitomycin C (MMC) and blockage of the lymphocyte function-associated antigen-1/intracellular adhesion molecule-1 (LFA-1/ICAM-1) pathway in recipients by species-specific mAbs] were tested for their ability to produce unresponsiveness to secondary islet xenografts.

METHODS

Collagenase-digested WS (RT1k) rat islets, purified by Ficoll density gradient, were incubated for 30 min with MMC 10 microg/ml, cultured for 20 hr, and transplanted into the renal subcapsular space of streptozotocin-induced diabetic C57BL/6 (H-2b) mice. Recipient mice were divided into experimental groups according to anti-rat ICAM-1 and/or anti-mouse LFA-1 mAb treatment and transplantation of MMC-treated or nontreated islets.

RESULTS

MMC pretreatment alone prolonged graft survival, with a mean survival time (MST) of 23.0+/-7.4 days, compared with that of cultured islets (12.4+/-2.7 days; P<0.01). MMC treatment of islets significantly augmented graft survival, compared with that of crude islet grafts under treatment with anti-donor ICAM-1 mAb (MST: >41.3+/-30 vs. 16.6+/-5.4 days, P<0.01), anti-recipient LFA-mAb (MST: >70.3+/-28.9 vs. 30.4+/-10.4 days, P<0.001), or both mAbs (MST: >88.1+/-24.1 vs. 23+/-7.4 days, P<0.0001). One of six, four of nine, and six of eight animals accepted MMC-treated islet xenografts over 100 days after treatment with anti-rat ICAM-1, anti-mouse LFA-1, or both mAbs treatments, respectively, whereas none of the animals accepted nontreated islets under the same treatment. When the mice bearing long-term functioning xenografts were challenged with the secondary graft from the original donor strain, the animals previously treated with anti-recipient LFA-1 and anti-donor ICAM-1 mAbs were more prone to accept it than animals given anti-recipient LFA-1 mAb alone (MST: 55.8+/-25.7 vs. 15+/-2.4 respectively; P<0.001), although they rejected the third-party xenograft and allograft acutely.

CONCLUSIONS

In the xenogeneic islet transplantation model, MMC graft pretreatment and blockage of the ICAM-1/LFA-1 pathway constitute a potent protocol for inducing unresponsiveness to islet xenografts.

Estimation of the lethal toluene concentration from the accidental death of painting workers

To determine the potentially lethal level of thinner concentration in the air, we measured the concentration of toluene in the blood and others of three patients who suffered severe acute thinner intoxication between 4 January 1996 and 21 April 1997 in Ube city. The concentration of toluene in blood were 30.2 mg/L in died patient, and 13.7 mg/L and 17.5 mg/L in recovered patients, respectively. By extrapolation from the results of our previous toxicokinetic research on toluene poisoning in anesthetized dogs, the fatal concentration of toluene was estimated to be approximately 1800 to 2000 ppm for 1-hour exposure.

Prevalence of Japanese dialysis patients with an A-to-G mutation at nucleotide 3243 of the mitochondrial tRNA(Leu(UUR)) gene

BACKGROUND

A high prevalence of an A-to-G mutation at nucleotide 3243 of the mitochondrial genome in patients with diabetes mellitus (DM) and/or deafness has been reported previously. We investigated the prevalence of this mutation in Japanese dialysis patients with associated DM and/or deafness.

METHODS

We studied 106 dialysis patients with DM, 26 with DM and deafness, and 26 with deafness alone, using peripheral leucocytes to detect an A-to-G transition at nucleotide 3243 of the mitochondrial gene.

RESULTS

We identified this transition in 1 of 26 patients with DM and deafness. None of the 106 DM or 26 dialysis patients with deafness but no DM was positive for this mutation. A 42-year-old male patient on continuous ambulatory peritoneal dialysis (CAPD) who carried this mutation had a 20-year history of sensory hearing loss as well as hypertrophic cardiomyopathy.

CONCLUSION

We found that a mitochondrial gene mutation at nucleotide 3243 was present in one dialysis patient with NIDDM and deafness. The prevalence of this mutation was found to be below 1% in diabetic end-stage renal disease patients in Japan.

PTEN / MMAC1 mutation and frequent loss of heterozygosity identified in chromosome 10q in a subset of hepatocellular carcinomas

Frequent allelic losses on chromosome 10q have been reported in several types of cancers, suggesting the presence of a putative tumor suppressor gene(s) on the chromosomal arm. We examined loss of heterozygosity (LOH) on chromosome 10q in 37 hepatocellular carcinomas (HCC) using eleven dinucleotide microsatellite markers, spanning the entire chromosome arm of 10q. Twelve (32%) out of 37 informative cases showed allelic losses of at least one locus on 10q and eight tumors showed a partial deletion of 10q. Analysis of deletion mapping of these eight cases identified two commonly deleted regions within the distal part of 10q (10q24-q26), a 20-cM interval flanked by D10S597 and D10S216 and a 24-cM interval flanked by D10S216 and D10S590. Moreover, we detected a somatic missense mutation (Met --> Val) of a candidate tumor suppressor gene PTEN / MMAC1, located at 10q23.3, in one HCC with LOH of 10q. Our findings indicated the presence of putative tumor suppressor gene(s) in the distal region of 10q that might be involved in the development and progression of HCC. Inactivation of PTEN / MMAC1 gene located outside the commonly deleted region of 10q might also play an important role in a subset of HCCs.

Creatol, an oxidative product of creatinine in hemodialysis patients

Creatol (CTL) is a product resulting from the reaction of creatinine (Cr) with the hydroxyl radical and is identified as a precursor of methylguanidine (MG), a uremic toxin. In this study, we investigated serum CTL levels together with those of Cr and MG in 66 patients who were on maintenance hemodialysis (HD). Prior to dialysis, the mean serum levels of Cr, CTL and MG were 967 (= 11.1 mg/dl)+/-267 microM, 11.1+/-4.8 microM and 5.8+/-2.9 microM, respectively. The mean CTL level was about 1.1% that of Cr, and the CTL plus MG level was about 1.4% that of the Cr level. The reduction rates of Cr, CTL and MG by a single HD were 62.6 6.1%, 71.0+/-10.3% and 51.9+/-11.6%, respectively. The CTL level at 0.5, 1 and 6 h after HD increased rapidly by 20.7+/-8.7%, 31.7+/-14.7% and 80.1+/-27.3%, respectively. There was a significant correlation between CTL or CTL/Cr and parathyroid hormone in patients who had just undergone parathyroidectomy. No significant correlation was found between CTL or CTL/Cr and those factors which seems to be related to the predialysis levels of reactive oxygen. Therefore, because of the good clearance of CTL and its rapid conversion to MG, its usefulness for the estimation of hydroxyl radical generation in HD patients is limited.

Measurement of hepatocyte growth factor in serum and plasma

To investigate whether serum or plasma should be used for the measurement of blood hepatocyte growth factor, the levels were compared in 28 normal subjects and 30 patients who had undergone surgery. The serum level was significantly higher than the plasma level. The serum and plasma hepatocyte growth factor levels differed markedly depending on the subjects, although overall there was a significant correlation between levels (r=0.862, P=0.0001). In serum obtained by the clotting of platelet- or leukocyte-containing plasma with thrombin, hepatocyte growth factor increased in proportion to the number of leukocytes. The difference between serum and plasma hepatocyte growth factor levels also correlated with the number of leukocytes in the patients (r=0.642, P=0.0004). Such a correlation was not observed for platelets. These findings suggest that the serum hepatocyte growth factor level does not strictly reflect the in vivo blood level, due to the release from leukocytes during sample preparation (i.e., blood clotting ) and that plasma is more suitable for assay of blood hepatocyte growth factor.

Evaluation of preoperative and intraoperative arterial stimulation and venous sampling for diagnosis and surgical resection of insulinoma

BACKGROUND

The precise intraoperative localization of insulinoma is essential for successful surgical treatment. In addition to various imaging modalities developed recently, arterial stimulation and venous sampling (ASVS) has also been used for tumor localization.

METHODS

Preoperative and intraoperative ASVS procedures were performed in 6 patients with insulinoma. Intraoperative ASVS was performed before and after tumor resection. Immunoreactive insulin (IRI) concentrations and the IRI ratio (IRI concentration at each time interval after calcium injection/baseline IRI concentration) were determined by the conventional or a quick IRI method.

RESULTS

The site of the tumor was identified preoperatively in all patients. The peak of the IRI ratio varied widely, but setting the cutoff value at 3.0 clearly differentiated peak IRA ratios in feeding arteries from those of nonfeeding arteries. Intraoperative ASVS showed a similar elevation of IRI levels, but the elevation disappeared after tumor resection in all but 1 patient. In 2 patients, resection of the tumor was confirmed during surgery by measuring IRI levels by the quick IRI method.

CONCLUSIONS

A combination of ASVS and conventional imaging modalities is useful for precise localization of insulinoma. Resection of the tumor can be confirmed intraoperatively by comparing IRI levels associated with preoperative and postresective ASVS.

[Clinical study of high-dose chemotherapy with peripheral blood stem cell transplantation for poor-risk germ cell tumor]

Between January 1997 and December 1998, six patients with germ cell tumor were treated with high-dose CEC: carboplatin (1,500 mg/m2), etoposide (1,200 mg/m2) and cyclophosphamide (100 mg/kg), followed by peripheral blood stem cell transplantation (PBSCT) at Nagoya University Hospital. Four patients received one cycle of high-dose CEC and two received two cycles. The reasons why the high-dose CEC was administered included: 1) refractory to the induction chemotherapy (AFP/beta-HCG elevated during the induction chemotherapy or prolonged half-life of each marker) in three patients, 2) relapse in two patients, and 3) consolidation in one with unresectable mediastinal residual tumor. There were no treatment-related deaths and grade 1 hepatotoxicity occurred in one (17%) patient. The median duration (range) from PBSCT until a granulocyte count of 500/microL and a platelet count of 50,000/microL was 8.5 (8-11) and 11 (9-16) days, respectively. Of the six patients studied, 5 responded to the treatment; two achieved a complete response (CR) and three achieved a partial response (PR). One patient achieving a CR and two achieving a PR remained in complete remission after 23 to 24 months of follow-up, while the remaining patients with a CR, a PR and an incomplete response died of the disease. High-dose CEC could be administered without serious toxicity but the effectiveness of high-dose CEC for the poor-risk patients with germ cell tumor needs to be further investigated.

A randomized comparative study of the Bandloop versus the standard loop for transurethral resection of the prostate

PURPOSE

The Bandloop is a new electroresection loop that is broader than the standard loop and thickens from front to back. We compared the safety and efficacy of the Bandloop to the conventional loop electrode for transurethral prostatectomy.

MATERIALS AND METHODS

A randomized prospective study was performed on 53 patients with lower urinary tract symptoms and estimated prostatic volume greater than 30 ml. on transrectal ultrasonography. The Bandloop was used in 25 cases (Bandloop group) and standard loop was used in 28 (standard group). Surgical outcomes, including International Prostate Symptom Score, resected prostatic weight, operative time, uroflowmetry, post-void residual urine, postoperative catheterization period, time to disappearance of macrohematuria, and serial changes of hemoglobin and urinalysis, between the 2 groups were compared.

RESULTS

A total of 23 Bandloop and 28 standard loop cases were evaluable. There was no difference in preoperative estimated prostatic volume (mean 44.7 versus 47.8 ml.), resected prostatic weight (36.5 versus 29.4 gm.) or operative time (61 versus 60 minutes) between the 2 groups. The ratio of resected weight-to-estimated prostatic volume was significantly greater in the standard group (81.4% versus 61.9%). There was no difference in postoperative catheterization period (3.3 versus 3.4 days) or time to disappearance of macroscopic hematuria (5.0 versus 5.0 days). Postoperative changes in symptom score (-15.1 versus -15.9), maximum flow rate (11.8 versus 16.3 ml. per second at 12 weeks) and residual volume (-31.6 versus -48.6 ml. at 12 weeks) demonstrated no significant difference between the 2 groups. There was no difference in intraoperative and postoperative bleeding estimated by serial changes in serum hemoglobin and urinalysis after surgery. No patient had major complications or required transfusion.

CONCLUSIONS

Transurethral prostatectomy using the Bandloop is as safe and effective in achieving subjective and objective improvements as standard transurethral prostatectomy. However, our randomized study indicates that the Bandloop offers no advantage compared to the standard loop electrode for transurethral prostatectomy.

Participation of the liver in generation of a vigorous anti-donor response after inoculation of donor spleen cells

BACKGROUND

There is a general agreement that a preferential accumulation of alloantigens within the liver could induce hyporesponsiveness to the inoculated antigens. Entrapment of antigens in the liver may evoke an unique immune response in the organ and play a key role in determination of the fate of the transplanted grafts. To understand the immune response in the liver after inoculation of allogeneic donor antigens, we examined the immune response to systemically inoculated alloantigen in rats whose sensitized liver was replaced with that of naive rats or in naive rats whose liver was replaced with that of sensitized rats.

METHODS

Using implantation of syngeneic liver (alloantigen-accumulated/naive) in rats (naive/alloantigen-sensitized), we compared the immune responses to alloantigen between rats with hepatic/extrahepatic alloantigen at 24 hr after alloantigen inoculation. This was called sensitized-liver-grafted (SLG)/sensitized-liver-removed (SLR) treatment. The immune response to donor alloantigen in this model was evaluated by survival of skin or heart grafts, complement-dependent cytotoxicity (CDC) titer and delayed-type hypersensitivity (DTH) response.

RESULTS

Compared with the mean survival time (MST) in donor spleen cell inoculated (DSI) rats (skin and heart, MST: 8.2+/-1.1 and 10.7+/-2.3 days), SLG rats rejected allografts in an accelerated fashion (skin and heart, MST: 5.5+/-0.5 and 4.2+/-0.8 days), associated with higher CDC titer and DTH response. In contrast, allograft survival was moderately prolonged in SLR (skin and heart, MST: 16.5+/-2.6 and 29.5+/-3.7 days) associated with suppressed CDC titer and DTH response. The survival of third-party allograft after SLG or SLR treatment (skin, MST: 9.3+/-1.5 or 9.7+/-0.6 days) indicated that immunological hyper/hyporesponsiveness was donor-specific.

CONCLUSIONS

A strong anti-donor immune response was induced by the transfer of donor antigen-baring liver to naive rats 24 hr after alloantigen inoculation, whereas removal of the liver suppressed alloimmune response. Our results indicate that vigorous anti-alloimmune response occurred in the liver after systemic inoculation of donor spleen cells.

Prognostic value of pressure-flow study in surgical treatment of benign prostatic obstruction

The prognostic value of pressure-flow study (P-FS) in the surgical treatment of bladder outlet obstruction (BOO) was retrospectively studied in patients with benign prostatic hyperplasia. In 74 patients who underwent surgical treatment for BOO, P-FS and free uroflowmetry were performed pre- and postoperatively. On P-FS, obstruction and detrusor contractility were analyzed according to the Schäfer nomogram. The patients were classified into the following 3 groups according to their preoperative P-FS: group A consisted of 39 patients with normal detrusors and obstruction (obstruction grade 3-6); group B consisted of 13 patients with weak detrusors and obstruction; and group C included 22 patients with weak or very weak detrusors combined with minimal obstruction, if any (obstruction grade 0-2). Postoperatively, the detrusor pressure at maximal flow rate and obstruction grades on P-FS improved significantly in groups A and B but not in group C. The rate of improvement was most prominent in group A, followed by groups B and C. On free uroflowmetry, however, a significant improvement occurred in all three groups with respect to maximal flow rate, average flow rate, and postvoid residue. Moreover, the rate did not differ among the three groups except for the maximal flow rate as determined between groups A and C. Although good detrusor contractility and evident obstruction on analysis of P-FS will guarantee the best surgical outcome, subjects with weak detrusors and minimal obstruction will also have a good outcome by the relief of BOO. In the weak detrusor, P-FS may be limited in diagnosing obstruction and have a low prognostic value, and such patients should not necessarily be excluded from surgical indications.

[Congenital arteriovenous malformation of the scalp with a drainage to the transverse sinus: a case report]

Arteriovenous malformation (AVM) of the scalp is uncommon, and a subtype which has connection with the intracranial dural sinus is extremely rare. Only 3 cases have been reported. We present a case of congenital AVM of the scalp which was connected with the intracranial venous sinus. A 27-year-old woman had been noted as having a pulsatile soft mass in the midline of the occipital region since her birth. She visited our hospital because of pain and enlargement of the mass. The patient had had no history of trauma. Physical examination revealed a pulsatile scalp mass in the midline of the occipital region, measuring 3.5 x 3.5 x 1 cm. A loud bruit was ausculated. Tenderness was noted. The skin over the mass was slightly reddish. No focal neurological deficits were noted. Plain skull films demonstrated a round defect in the midline of the occipital bone. Magnetic resonance imaging (MRI) demonstrated a subcutaneous mass with low signal intensity and an infratentorial mass with flow void. 3D CT angiograms demonstrated a subcutaneous vascular mass with a single large vein draining into the right transverse sinus. External carotid angiograms revealed a vascular lesion within the scalp with supply from the branches of the bilateral occipital arteries and the meningeal arteries. The nidus penetrated the skull and connected to a dilated varix, which had a draining vein shunting into the right transverse sinus. After embolization of the right meningeal feeding arteries, surgery was performed. The vascular lesion penetrated the skull and the dura. The infratentorial mass was in the epiarachnoid space and was fed by a small pial artery. The mass was excised completely after interruption of the pial artery and the draining vein. Postoperative course was uneventful. Histologically, the subcutaneous mass and infratentorial vascular mass were shown to be AVM and varix, respectively.

Enhancement of osteogenesis in vitro and in vivo by a novel osteoblast differentiation promoting compound, TAK-778

TAK-778 [(2R,4S)-(-)-N-(4-diethoxyphosphorylmethylphenyl)-1,2,4, 5-tetrahydro-4-methyl-7, 8-methylenedioxy-5-oxo-3-benzothiepin-2-carboxyamide; mw 505.53], a novel osteoblast differentiation promoting compound, was characterized in vitro and in vivo models. TAK-778 at doses of 10(-6) M and higher promoted potently bone-like nodule formation in the presence of dexamethasone in rat bone marrow stromal cell culture. This was accompanied by increases in cellular alkaline phosphatase activity, soluble collagen release, and osteocalcin secretion. Under the culture conditions, TAK-778 also stimulated the secretion of transforming growth factor-beta and insulin-like growth factor-I, indicating that TAK-778 may exert regulatory effects on osteoblast differentiation via autocrine/paracrine mechanisms. Furthermore, the in vivo osteogenic potential of TAK-778 was studied in bony defect and osteotomy animal models, using sustained release microcapsules consisted of a biodegradable polymer, poly (dl-lactic/glycolic) acid (PLGA). Single local injection of TAK-778/PLGA-microcapsules (PLGA-MC) (0.2-5 mg/site) to rat skull defects resulted in a dose-dependent increase in new bone area within the defects after 4 weeks. When the pellet containing TAK-778/PLGA-MC (4 mg/pellet) was packed into place to fill the tibial segmental defect in rabbit, this pellet induced osseous union within 2 months, whereas the placebo pellet did not. In addition, single local application of TAK-778/PLGA-MC (10 mg/site) to rabbit tibial osteotomy site enhanced callus formation accompanied by an increase in breaking force after 30 days. These results reveal for the first time that a nonendogenous chemical compound promotes potently osteogenesis in vitro and enhances new bone formation during skeletal regeneration and bone repair in vivo and should be useful for the stimulation of fracture healing.

Evaluation of regional liver function by gadolinium-EOB-DTPA-enhanced MR imaging

We evaluated the role of magnetic resonance (MR) imaging with gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA), in estimating regional liver function in a rat ischemia-reperfusion model. Ischemic liver damage was induced in the right lobe by vascular clamping for 0 (sham), 30 (I-30), 60 (I-60), and 90 min (I-90 group). The ischemic lobes in the I-60 and I-90 groups was clearly visualized as a high intensity area in the T1 images at late phase of Gd-EOB-DTPA enhancement, Moreover, the T1/2 of signal intensity in ischemic lobes significantly correlated with the duration of vascular clamping. We also observed significant correlation between T1/2 and ATP concentration in the liver tissue (r = -0.719, P = 0.04). Our results indicate that MR imaging with Gd-EOB-DTPA is useful for evaluation of regional liver function in rats.

Imaging of hydroperoxides in a rat glomerulus stimulated by puromycin aminonucleoside

BACKGROUND

To determine the locus of the increased oxidation induced by puromycin aminonucleoside (PAN), we imaged hydroperoxides in glomeruli stimulated by PAN in vivo and in vitro.

METHODS

Dichlorofluorescein diacetate (DCFH-DA) in cells makes dichlorofluorescein, a substance that fluoresces when reacted with hydroperoxides. Fluorescence was detected using a photon detection video camera connected to a microscope. Two kinds of isolated glomeruli of Wistar rats were examined. One was the glomerulus obtained from rats on the seventh day following the injection of PAN. In this case, glomeruli were incubated in a buffer containing 5 mM DCFH-DA. Another was the glomerulus collected at 30 minutes after a large amount of DCFH-DA was intravenously injected. These glomeruli were incubated with either PAN or phorbol myristate acetate (PMA) in Krebs-Henseleite bicarbonate buffer.

RESULTS

The images from the glomeruli treated by PAN in vivo resemble pictures of a galaxy by telescope. When the glomeruli were treated by PAN in vitro, two localized points appeared in each glomerulus after 15 minutes of incubation with PAN, and after 75 minutes of incubation, the fluorescence spread throughout the glomerulus. When glomeruli were incubated with PMA, two points that gave a very strong fluorescence were observed in each glomerulus, but they did not spread throughout the glomeruli. In both experiments, glomeruli without stimulants did not fluoresce.

CONCLUSION

Increases in hydroperoxides were observed in the glomeruli from rats made nephrotic by exposure to PAN, and were also observed in glomeruli following 15 minutes of incubation with PAN in vitro.